Method of treating color photographic materials



April 7, 1942.

B. GAsPAR ETAL METHOD OF TREATING COLOR PHOTOGRAPHIC MATERIALS FiledMarch 27, 1940 I I SUPPORT BLUE SENSITIVE SILVER HALIDE YELLOW' FILTERDYE GREEN SENSITIVE SILVER HALIDE REDUCIBL RED cmmm DYE AND PANCHROMATICSILVER HALIDE AND REDUCIBLE RED DYE SUPPORT BLUE SENSITIVE SILVER HALIDEYELLOW DYE AND CATALYST ORTHOCHROMATIC SILVER HALIDE AND YELLOW DYESUPPORT BLUE SENSITIVE SILV AND CATALYST ER HALIDE FIG. 3.

' terial.

Patented Apr. '7, 1942 UNITED STATES PATENT OFFICE 1 METHOD or, TREATINGooLo'a PHOTOGBAPHIG MATEltIALS Bla Gaspar, Hollywood, Calif and LaszloSchwarc. Brussels, Belgium, assignors, by direct and mosne assignments,to Chromogen, 'Incorporated,a corporation of Nevada Application March27, 1940, Serial No. 326,270 In Great Britain March 29,1939

(]. 95- 2) x of the diiferent layers of .which and more specia; Claims.-

The present invention relates to a photographic material and to methods'of treating the same. 7 For many photographic purposes-multilayermaterials are known in which some of the layers which are to becolorless in the final multicolor picture are uniformly dyed during themanufacture or during. the treatment of the multilayer 'material andhave to be decolorized by a treatfically that layer that is colored oristo be colored by a. reducible dye and that later on is to be uniformlybleached contains a'substance that is capable of accelerating thereduction of the dye by reducing agents. Suitable acceleratingsubstances are, inter alia, phenazine compounds and quinoxalinecompounds. These substances may be incorporated into a filter layer orinto a lightsensitive emulsion layer and if desired they may beprecipitated within the layer either by precipitating agents or by thedye itself.

The dyes used are preferably substantive and acid azo dyes.

A suitable reducing agent is a titanium trichloride solution or adiluted 'hydrosulphite solution or a solution of formaldehyde sodiumsulphoxyllayer material in which at least two layers are dyed byreducible dyes, the one layer containing an addition which influencesthe bleaching speed of the dye to such an extent that the dye presentwithin the said one layer can be totally bleached within a. periodin'which the dye -pres-- ent within the other layer is. scarcelyaffected. The speed-influencing substance may be an accelerator presentwithin the layer to be selectively bleached or a retarder present withinthe layer not to be bleached. An accelerator within ate (SchultzFarbstofftabellen, Leipzig 1932, 7th

chloride may also be used.

Photographic layers containing the dye and the accelerating substanceare bleached in a considerably shorter time than layers without theaddition. Thus, for example a gelatin layer the one layer and a retarderwithin the other 7 layer may also be applied. Preferably, theaccelerator and/or the retarder as well as their conversion productsshould have a negligible tendency to wander from one layer into theother.

It is a further object of the present invention to provide aphotographic material which is particularly suitable for carrying outthe selective bleaching of one layer without simultaneously bleachinganother layer which may contain the same or a different dye,

The invention is based partly upon the known fact that certain dyes arebleached byreducing agents only with great difllculty, but that thereaction can beaccelerated by the addition 01 catalysts to the bleachingsolution. .7

Figures 1, 2 and 3 of the drawing disclose cross sectional views ofmaterials with the layers drawn to an. enlarged scale which illustratemodifications of the improved photographic ma For carrying out theprocess according to the present invention a material may be used, one

hydrochloric acid containing .45% "2,3-diaminophenazine the dye will bebleached completely within 4 minutes. A gelatin layer dyed withSupranolbrillantrot 3BL or 3B (Schultz Farbstoiitabellen, Leipzig 1932,7th ed., vol. 2, page 204) will be bleached within 3 minutes if treatedin the same manner with 2,3-diaminophenazine,

whereas without such treatment the bleaching requires more than 20minutes.

Layers containing the accelerating substance may be processed in variousmanners for which the following examples may be given.

Example 1 The multilayer material disclosed in Figure 1 is in the formof a bipack having two supports 1 and 2, three silver halide emulsionlayers' 3, 4

- and 5 and two filter layers 6 and -l, the front for about 8 8 coatedthereon. The second support 2 is coated with a panchromatic silverhalide emulsion layer dyed with Supranolbrillantrot 3BL or 3B (SchultzFarbstofitabellen, l. c.), a superposed gelatin filter layer 1 equallycolored red with Supranolbrillantrot 3BL or 3B and another silver halidelayer 4 which is sensitive to green. The three light-sensitive layers 3,4 and 5 are arranged between the two supports i and 2. The red dyedfilter layer 1 contains 1 gram per square metertetrabromodimethylquinoxaline obtainable by heating in glacial aceticacid 1 mol o-phenylenediamine with 1 mol sym. tetrabromodiacetyl(Keller, Berichte der Deutschen Chemischen Gesellschaft, v01. 23, p e35, 1890). The two parts of the bipack are developed after exposure andfixed. The silver image formed in the front element may be used as a.printing proto-type or may be converted into a dye image. The rearelement of the bipack is treated with a solution of 1 gramtitanium-trichloride in 100 ccs. .04- normal hydrochloric acid, whichacts to de- 'stroy the dye in the filter layer containing the frontlayer of the rear film is dyed with Chrysophenine G (SchultzFarbstoiftabellen, l. c.)"and thereafter the film" having a silver imageuniformly dyed yellow in the one layer and a silverimage uniformly dyedred in the other layer, is subjected to the action of a thiocarbamidesolution or other suitable treating solution such as a hydrobromic acidwhich bleaches the dyes locally and yields, after the removal of thesilver images, a two-color-image colored magenta and yellow and whichmay be used as a printing proto-typ Example 2 The photographic materialdisclosed in Figure 2 comprises an orthochromatic silver halide emulsionlayer 9 dyed with 1 gram Chrysophenine G (Schultz Farbstoiftabellen, l.c.) per square meter and a superposed filter layer III of gelatincontaining 1 gram Chrysophenine G and 1 gramtetrabromo-dimethyl-quinoxaline per square meter. An uncoloredblue-sensitive silver halide emulsion layer 8 is coated on top of thefilter layer it. The multilayer material is exposed, developed andfixed, and the front layer 8 is colored by immersing the material in asolution of Supranolbrillantrot 3BL or 3B. This red dye colors thesurface layer 8 and possibly also the filter layer. The dyeing processshould be stopped before the yellow coloredsilver emulsion layer 9 isdyed. -If now the film is treated with a titanium trichloride solutionas in Example 1,

the red dye that might have colored the filter layer will be destroyed.The dyes present in the two silver layers are hardly affected by thistreatment. They are then locally destroyed by a solution ofthiocarbamide or hydrobromic or hydrochlo'ric acid.

Example 3 for several hours.

Figure 3') may be present in the blue-sensitive layer I3. Afterexposure, development and fixing, and after the removal of the filterdye, the two uncolored layers are dyed with Supranolbrillantrot 3BL or3B. Thereafter the film is treated with a reducing agent, for examplewith the tit'anium trichloride solution specified in Example 1, whichdecolorizes the upper layer without materially affecting the' lowerlayers. The decolorizedupper layer is thereafter recolored with adifferent dye, e. g., Pontamine Sky Blue 63x (Schultz Farbstofltabellen,Leipzig 1931, 7th ed., vol. I, No. 510), and the three dyes are locallydestroyed at the places where silver is present by treating the materialwith thiocarbamide or hydrohalic acids.

It is often advisable to incorporate a precipitating agent into thelayer in which the dye should not be decolorized by the treatment withthe reducing agent, because it has been found that if the dye isprecipitated it is more resistant to reducing agents, and thus thedifference between the bleaching speeds brought about by in" corporatingan accelerator into the layer to be I decolorizedcan be increased stillfurther by the incorporation of a precipitant into the layer whichshould not be decolorized. A suitable precipitant for "the dyeSupranolbrillantrot 3BL or 3B is, for example, the diacetate ofdiphenyl-4,

4'-dibiguanide of the formula Again for example a gelatin layer dyedwith Pontamine Sky Blue 63X (Schultz Farbstofltabellen, Leipzig 1931,7th edition, vol. 1, No. 510) is completely decolorized within a fewseconds if treated with a normal sodium carbonate solution containing 2%sodium hydrosulphite and 25% anthraquinone-p-sulphonic acid. If,however, prior to this treatment, the layer is treated for 8 minuteswith a 1% solution of the diacetate of 3, 3'-dimethy1-diphenyl-4,4'-dibiguanide of the following formula NHrc-Nn-c-Nn- NH-C-NIFC-NH:

1%: 1h! L on IE3 IE3 there is no visible eflect in twominutes.

A gelatin layer dyed with Supranolbrillantrot 3BL or 3B is completelydecolorized within 8 minutes if treated with a solution of 1% sodiumhydrosulphite in .2 n-sodium carbonate. On the other hand, a priortreatment for 8 minutes in 1% ortho-tolidine-di-biguanide acetatesolution results in complete decolorization being retarded What isclaimed is:

1. The process of producing photographic dye images from a photographicmultilayer film comprising at least two colloid layers on a singlesupport, one of said colloid layers being uniformly dyed with a dye forthe production of a dye image within said layer, said dye beingdestroyable with a reducing agent, another of said colloid layers beinguniformly dyed with substantially the same dye, atleast the first ofsaid layers comprising a photographic silver =image, the multilayer filmfurther comprising a substance which is capable of influencing thebleaching speed of said reducing agent with respect to said dye andselected from' the group which consists of speed retarding agentspresent in the firstnamed layer and reduction catlysts present in thesecond-named layer, which comprises treatdye, at least the first of saidlayers comprising a stance which'is capable of destroying the dye byreduction in the presence of metallic silver only to produce thereby adye image in the first layer with the aid of the silver image andremoving the silver image. 7

2. The process of producing photographic multicolor dye images from aphotographic multilayer film comprising at least two colloid layers on asingle support, one of said colloid layers being uniformly dyed with adye for the production of a dye image within said layer, said dye beingdestroyable with a reducing agent, another of said colloid layers beinguniformly dyed with 4 substantially the same dye, each of said layerscomprising a photographic silver image, representing difierent coloraspects of a multicolor image, respectively, the multilayer film furthercomprising a substance which is capable of infiuencing the bleachingspeed of said reducing agent with respect to said dye and selected fromthe group which consists of speed retarding agent present in thefirst-named layer and reduction catalysts present in the second-namedlayer, which comprises treating said two layers with said reducing agentto destroy thereby completely the dye by reduction within said secondlayer only, recoloring said layer with a difierent reducible dye andthereafter treating said film with the solution of a substance which iscapable of destroying said dyes by reduction in the presence of metallicsilver only, to produce thereby diiierently colored dye images withinsaid layers with the aid of the silver images and removing the silverimages. V

3. The process of producing photographic multicolor dye images from aphotographic multilayer film comprising at least two colloid layers on asingle support, one of said colloid layers being uniformly dyed with adye for the production of a dye image within said layer, said dye beingdestroyable with a reducing agent, another of said colloid layers nearerthe surface than said first mentioned layer being uniformly dyed withsubstantially the same dye, each of said layers comprising aphotographic silver image representing difierent color asp ts of amulticolor image, respectively, the multilayer film further comprising asubstance which is capable of influencing the bleaching speed of saidreducing agent with respect to said dye and selected from the groupwhich consists of speed retarding agents present in the first-namedlayer and reduction catalysts present in the second-named layer, whichcomprises treating at least said second layer with said reducing agentto destroy thereby completely the dye by reduction within said layeronly, recoloring the layer with a different reducible dye and thereaftertreating said I film withthe solution of a substance which is capable ofdestroying said dyes by reduction in the presence of metallic silveronly, to produce thereby differently; colored dye images within saidlayers with the-aid of the silver images, and removing 'the silverimages.

4. A photographic multilayer film comprising at least two colloid layerson a single support, one of said colloid layers being uniformly dyedwith a dye for the production of a dye image within said layer, said dyebeing destroyable with a reducing agent, another of said colloid layersbeing uniformly dyed with substantially the same treating said twolayers with said reducing agent photographic silver image, themultilayer film further comprising a substance which is capable ofinfluencing the bleaching speed of said reducing agent with respect tosaid dye and selected from the group which consists of speed retardingagents present in the first-named layer and rea reducing agent saidlayer containing. further a substance which is capable of retarding thebleaching speed of said reducing agent with respect to said dye, anotherof said colloid layers being uniformly dyed with substantially the samedye and containing a reduction catalyst, at least the first of saidlayers comprising. a photographic silver image.

6. The process of producing photographic dye images from a photographicmultilayer film comprising at least two colloid, layers on a singlesupport, one of said colloid layers being uniformly dyed with a dye forthe production of a dye image within said layer, said dye beingdestroyable with a reducing agent, another of said colloid layers beinguniformly dyed with a dye which is not required for the production of adye image within said layer and which is destroyable by said reducingagent, said last mentioned dye having approximately the same bleachingspeed with respect to said reducing agent as has said first mentioneddye, at least the first of said layers comprising a photographic silverimage, the'multilayer film further comprising a substance which iscapable of influencing the bleaching speed of said reducing agent withrespect to said dyed layers and selected fromthe group whichconsists ofspeed retarding'agents present in the first-named layer and reductioncatalysts present in the second-named layer, which comprises to destroythereby completely the dye-by reduction within said second layer onlyand thereafter treating said film with the solution of a substance whichis capable of destroying the dye by reduction within said first layer inthe presence of metallic silver only to produce thereby a dye image inthe first layer with the aid of the silver image and removing the silverimage.

7. A photographic multilayer film comprising at least two colloid layerson a single support, one of said colloid layers being uniformly dyedwith a dye for the production of a dye image within said layer, said dyebeing destroyable with a reducing agent, another of said colloid layersbeing uniformly dyed with a dye which is not required for the productionof a dye image within said layer and which is destroyable by saidreducing agent, said last mentioned dye having approximately the samebleaching speed with respect to said reducing agent as has said firstmentioned dye, at least the first of said layers comprising aphotographic silver image, the multilayer film further comprising asubstance which is capable of influencing the bleaching speed of, saidreducing agent with respect to said dyed layers and selected from thegroup which consists of speed retarding agents present in the firstnamed layer and reduction catalysts present in the second named layer.

8. A photographic multilayer film comprising at least two colloid layerson a single support,

one of said colloid layers having uniformly distributed therein a dyewhich is destroyable with a reducing agent said layer further containinga substance which is capable of retarding the bleaching speed of saidreducing agent with respect' to said dye, another of said colloid layersbeing uniformly dyed with a dye which is also destroyable bysaid'reducing agent and which has approximately the same bleaching speedwith respect to said reducing agent as has said first mentioned dye,said latter layer containing a reduction catalyst, at least the first ofsaid layers 5 comprising a photographic silver image.

1am GAsPAR. LASZLO SCHWARC.

